How to check storage on your Mac
macOS shows a storage bar, but it doesn't tell you why "System Data" or "Other" is so large. Here's how to see exactly what's using your disk space.
Check storage in About This Mac
The quickest way to see how your storage is used is through About This Mac:
- Click the Apple menu () in the top-left corner.
- Select About This Mac.
- Click More Info to open System Settings.
- Scroll down to Storage.
You'll see a color-coded bar showing how much space is used by different categories — apps, photos, documents, and the often-mysterious "System Data" and "Other" sections. This gives you a high-level overview, but it won't tell you exactly which files are consuming space.
Detailed breakdown in System Settings
For a more detailed view, open System Settings directly:
- Open System Settings (from the Apple menu or Spotlight).
- Navigate to General → Storage.
Here you'll see a breakdown of storage by category:
All installed applications, including their .app bundles
Files in your Documents folder, Desktop, and Downloads
Your photo library, including iCloud-synced images
Caches, logs, and system-managed files — often the largest mystery
Everything macOS can't neatly categorize, including app leftovers
Tip: Click the Recommendations section at the top of the Storage pane. macOS suggests actions like emptying Trash, storing files in iCloud, and reviewing large files — useful quick wins.
Browse storage with Finder
macOS hides the ~/Library folder by default because it contains important app data. But this is often where the biggest space hogs live.
- Open Finder.
- Press ⌘ Shift . to toggle hidden files visible.
- Navigate to your home folder and open the now-visible
Libraryfolder.
Inside ~/Library, check these folders — they're usually the largest:
Application Support— app databases, plugins, and large data filesCaches— temporary data that can often be safely deletedContainers— sandboxed app data (Mac App Store apps)
Why is Library hidden? Apple hides it to prevent accidental deletion of files that apps need to function. Modifying the wrong file can break apps, so proceed carefully — and always move files to Trash (not permanent delete) so you can undo with ⌘Z.
Check disk usage from Terminal
Terminal gives you precise, sortable numbers — great for finding exactly what's consuming space.
Overall disk usage
df -hShows total, used, and available space for all mounted volumes. Look at the row for your main disk (usually /System/Volumes/Data).
Library folder breakdown
du -sh ~/Library/*/ | sort -rh | head -20Lists the 20 largest subdirectories in your Library folder, sorted by size. This is the fastest way to find which apps are hoarding space.
Note: You may see "Operation not permitted" errors for some directories. This means Terminal doesn't have Full Disk Access. You can grant it in System Settings → Privacy & Security → Full Disk Access.